This invention relates to a process for the production of an evaporated milk product containing fats.
Evaporated milk or cream is prepared from whole milk or cream by partial elimination of the water which it contains. The effect of this concentration is to bring together the fatty globules which can cause the fats to rise during storage. Finally, evaporated milk has to be sterilized because it is intended for prolonged storage.
When sterilization is carried out by a thermal appertization treatment after packing, for example in cans, there is an increased risk of destabilization of the liquid phase by the heat applied due to the disturbance of the caseinate/calcium phosphate system after concentration. During storage, the milk thus treated can thicken and then gel. A typical method of overcoming this particular disadvantage is to add stabilizing salts, such as for example disodium phosphate or trisodium citrate. However, these additives are being contested to an increasing extent by food legislation.
One alternative to sterilization by appertization is aseptic packing of the evaporated milk which has been sterilized on-line, for example by ultra-high temperature or high temperature short-time. The latter process does not prevent harmful crystallization of the calcium citrate or even gelling during storage.